Something Odd about Ducks

Last night, my family had duck for dinner (except for me, but that's beside the point). So, today I was thinking about ducks, and I remembered this piece of trivia: A duck's quack does not echo.

How does someone figure that out? I mean, did someone put a duck in a tunnel and make it quack or something? Didn't they have anything better to do than make a duck quack in a tunnel and conclude that the quack didn't echo? And why didn't that quack echo? Are ducks part of an anti-echoing league or something? Think about it, people!

OK, I just realized that I have raised more questions than I should have. Sorry. I'll be quiet, now.

End